How to get my dog from eating her blanket?

I have a 8yr old terrier mix. She is crate trained and has exhibited mild chewing behaviors in the past (small carpet chunks, etc). She has not done this for almost two years but recently within the last couple of weeks, she has been chewing and eating chunks of the blanket that is in her crate. She has not been constipated and has passed them with her stool within a few days of eating them. I know she may have some seperation anxiety but how can I keep her from eating this while in her crate. She shares her crate with a 7 yr old chihuahua mix who likes to sleep underneath a blanket while in the crate, so it’s hard for me to take away all the bedding and punish one without affecting the other.

Thanks for any help/advice!